The biaxially drawn and blow molded bottles made of such a resin as polyethylene terephthalate (hereinafter referred to as PET) are now in use in various fields including beverages, foods, and cosmetics. Especially in those fields requiring a gas barrier property, use is made of laminated bottles in which an intermediate gas barrier layer of a nylon resin or a copolymeric resin of ethylene vinyl alcohol is laminated with layers of the main PET resin.
Patent document 1 discloses a biaxially drawn and blow molded bottle in which a layer of such a gas barrier resin has been laminated with the layers of the PET resin, and a process for molding a laminated preform in a shape of a test tube, which is a primary molded product used to mold the laminated bottle. FIGS. 20 and 21 show representative examples of such a bottle and a preform. The bottle 601 shown in FIG. 20 comprises a neck 602, a neck ring 603, a cylindrical body 605, and a bottom 606. In a height range excluding an upper portion of the neck 602 and the bottom 606, an intermediate layer 613 of the nylon resin having a gas barrier property is sandwiched between an outer layer 611 and an inner layer 612 both made of the PET resin.
The bottle 601 can be molded by biaxially drawing and blow molding the preform 501 shown in FIG. 21. This preform 501 comprises a neck 502, a neck ring 503, a cylindrical body 505, and a bottom 506. At a height range excluding the neck 502 and the bottom 506, an intermediate layer 513 of the nylon resin having a gas barrier property is sandwiched between an outer layer 511 and an inner layer 512 both made of the PET resin.